Thin film chromatography

E. W.Trutter, "Thin Film Chromatography", Interscience, NY (1963) 97)J. Hansson, Explosivst 1963, 73r7 (Thin-layer chromatographic method for separating ordinary expls) 98)D.M.Colman, AnalChem 35, 652-54 (1963) (Paper Chromatography of substituted trinitrobenzenes) 99)H.A. Szimanski, "Lectures on Gas Chromatography , Plenum Press, NY (1963) I00)W.A. 

The latex was cleaned by ion exchange and serum replacement, which gave the cleaned latex plus six serum fractions. The cleaned latex and the serum samples were analyzed by conductometric titration. Also, the amount of anionic emulsifier in the serum was determined by Fyamine 1622 colorimetric titration and thin-film chromatography, and the amount of nonionic emulsifier by iodine-iodide colorimetric titration and thin-film chromatography. 

The material balance of the strong-acid groups showed a theoretical total of 0.194 meq/gm polymer from the sodium lauryl ether sulfate, potassium persulfate, and sodium hydrosulfite, in comparison with a measured total of 0.205 meq/gm (0.026 on particle surface 0.179 in serum) by serum replacement and a total of 0.215 meq/gm by ion exchange with Dowex 50W(H+). The material balance of the acrylic acid showed that 29.9% was on the particle surface, 28.6% in the aqueous serum, and 41.5% buried inside the particle. The sodium lauryl ether sulfate found in the serum amounted to 78% of that added by Hyamine 1622 titration and 88% by thin-film chromatography. The nonylphenol polyoxyethylene adduct amounted to 113% by iodine-iodide titration and 91% by thin-film chromatography. ... 

Data obtained from STM images can be useful in providing information on the relative importance of molecule-molecule and molecule-substrate interactions, as well as the types of forces responsible for the packing order at the surface. This is useful in such applications as epitaxial growth of thin films, chromatography, lubrication, and microelectronics fabrication, each of which involves interactions between molecules on a surface and can be investigated by these procedures. 

It was already mentioned that thin film chromatography is used firstly as a qualitative analysis method. There is no accurate quantitative analysis that is possible by thin film chromatography. However, there is an empirical formula, equation (2.3), which allows the approximate calculation of the weight of the substance (W) from the spot area (A). This method is very inaccurate and can be used only for gross estimation. 

The thin film chromatography is the last chromatographic method discussed in this chapter. More about this method can be found in references 63-66 at the end of part I of this book. 

The first method is the most used. The second and third methods are usually used in connection with high performance liquid or thin film chromatography. 

E. V. Truter, Thin Film Chromatography, Wiley (Interscience), New York, 1963,... 

Truter, E. V. Thin Film Chromatography, 205 pages, published in 1963 [720]. 

Reflection can be either regular (at smooth surfaces) or diffuse (by material whose small particle size causes scattering). Diffuse reflection is used mainly in thin-film chromatography... 

Diffuse reflection has a wide range of uses, e.g., in research, where it is used in the observation of molecules adsorbed on a. surface [138] (especially in catalysis), and also in analysis (e.g., thin-film chromatography [89], [139]). To capture" as much of the diffusely reflected radiation as possible, an Ulbricht sphere is often used. This type of arrangement, in conjunction with optical fibers, is currently used in production lines in the automobile industry for quality control of bodywork paint 1140]. 

Halpaap, H. (1963). Preparative thin film chromatography. Chem.-Ing.-Tech. 35 488-493. 

Another approach to improving resolution is to use thin films of stationary phase. Capillary columns used in gas chromatography and the bonded phases commonly used in HPLC provide a significant decrease in plate height due to the reduction of the Hs term in equation 12.27. 

Fig. 24. A thin layer chromatography (TLC) image, documenting detection of impurities in a series of dye intermediate samples under near-UV illuinination. Columns 1 and 7 represent reference materials. Photographed with Polaroid Type 339 film in a CU-5 closeup camera.

Thin-layer chromatography has the great advantage that the result of the separation is stored — usually invisibly — on the TLC/HPTLC plate as on a diskette. In such cases it needs developing or detecting, rather like an exposed film. This can now be done online or off-line so that the analyst can decide which method to use to detect the separated substances. 

In practice, chromatography takes place on a layer or in a tube. Meyer [4] has compared analytical column-type chromatographic methods. A column can be an open capillary or a packed tube. In the first case the mobile phase is coated as a thin film on the inner wall of the capillary. In most cases GC is used as open-tubular... 

Fig. 3. Diagrams of electrochemical cells used in flow systems for thin film deposition by EC-ALE. A) First small thin layer flow cell (modeled after electrochemical liquid chromatography detectors). A gasket defined the area where the deposition was performed, and solutions were pumped in and out though the top plate. Reproduced by permission from ref. [ 110]. B) H-cell design where the samples were suspended in the solutions, and solutions were filled and drained from below. Reproduced by permission from ref. [111]. C) Larger thin layer flow cell. This is very similar to that shown in 3A, except that the deposition area is larger and laminar flow is easier to develop because of the solution inlet and outlet designs. In addition, the opposite wall of the cell is a piece of ITO, used as the auxiliary electrode. It is transparent so the deposit can be monitored visually, and it provides an excellent current distribution. The reference electrode is incorporated right in the cell, as well. Adapted from ref. [113],...

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